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    <title>Document</title>
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<body>
    <script>
        // 上午作业 3. 判断一个四位数字是平年还是闰年
        var year = +prompt("输入一个秒数");
        if(year % 4 === 0 && year % 100 !== 0 || year % 400 === 0){
            console.log("闰年");
        }else {
            console.log("平年");
        }
    </script>
</body>
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